Production of protective gas



I. IVIUCHKA.

PRODUCTION 0F PROTECTIVE GAS.

APPLICATION FILED IAN. 5| 1921.

Patented Apr. 18,' 1922.

infr/f narran @al VEENEG'A, AUSTRIA.

rneioucrrcrr or rnorncrrve ons.

trainees.

Specieation of Letters Patent. Patmubd Apg, 1h39 .applcatien filled .Zlanuary e, M231. Serial No. 435,554.

To all wm t may concern:

Be it known that l, Josnr Meo-nim, residing at 39 l/Vallgasse, Vienna Vil, Austria, have invented certain new and useful Tmprovements in and Relating to the Producs tion of Protective Gas, (for which l have filed applications in Austria Sept.A 24, 1915, and in Germany Feb. 7, 1917,) of which the following is a speciiication.,

ln large installations for the storage of highly inliammable liquids, which naturally require considerable quantities of protective gas, it is usual to' produce the latter with the aid of special machines on the premises. rThis has the advantage that a substitution for the protective gas of another gas kept in.

stock becomes impossible and the installation is independent of the delivery of the protective gas through other undertakings.

Such. protective gas producers consist substantially of an internal combustion engine, the waste gases of which, vconsisting of carbondioxide, nitrogen and water vapor, provide the protective gas, which is sucked through a suitable arrangement over a cool` ing and purifying device and is transmitted to a collecting vessel. These purified waste gases consisting mainly only of carbondioxide and nitrogen are thereupon converted in a known manner by means of a compressor into pressure gas and are used for superposition on the inflammable liquid.

It is essential for the use of such protective gas producers, that they shall only deliver protective gas, which is free from unburnt components, that is, such as contain oxygen.

This problem is solved according to the present invention by only such a quantity of combustion gases being taken from the cylinder of the internal combustion engine as protective gas, as is capable of flowing away during the explosion stroke in consequence of the pressure being above the pressure obtaining in the protective gas pipe. The remaining portion of the combustion gases is allowed to-escape into the atmosphere durin the following exhaust stroke.

he pressure above atmospheric, which still obtains only in the case of normal ignition at the 'end of the explosion stroke within the cylinder, provides complete safety against the conducting away to the protective gas pipe of unburnt gas mixtures which are present in the cylinder in the case of mistlres.v

The drawing off ofthe quantity of gas taken away at the end of the explosion strolre for the purpose of collectin it is eected in the simplest manner by ad ing a sf'gieciallyy controlled outlet or over-pressure member, to which is connected the protective gas pipe leading to the collector. This overpressure member vis opened towards the end of the explosion stroke and is again closed before the piston commences the exhaust.

lf, in consequence of a misre, there should not occur the great over-pressure in the 'cylinder due to the explosion alone, through lack of an over-pressure at the end of the idle stroke thus caused no gas can pass from thecylinder into the protective gas pipe. There will however bea backward flow of protective gas from the said pipe to the cylinder, as the pressure in the protective vgas pipe in this case is higher than the end pressure in the cylinder.

In the accompanying drawing two convstructional examples of protective gas producers working according to the described method are shown in Figures 1-4 diagrammatically in section. The diagrams shown in Figures 2 and 3 show the course of the pressure line during the compression stroke and explosion stroke, the former (Figure 2) when the engine is working normally, the latter (Figure 3) for the case of the ignition failing (misfire).

The apparatus consists, according to Fig,

ure 1, in a known manner, 'of an internal combustion engine which is preferably a four-stroke one, having the piston bworking in the cylinder a, the controlled inlet valve c and the controlled exhaust valve d.

For transferring the combustion gases, which must be first freed from Water vapor, into the protective gas collector, according vto the constructional form shown, a compressor is provided consisting of the cylinder e, the piston f of which is driven by the shaft g of the internal combustion engine. The compressor is provided with the "suce tion valve 7L and the pressure valve i, which latter controls the pressure pipe j leading to the protective gas collector (not shown).

According tothe invention there opens into the cylinder a of the internal combustion engine a pipe m which is closed by a valve le operating at a pressure above atmospheric, which leads through a cooling device n. and a purifier (not shown) to the suction valve h of the compressor.

The controlled valve k is opened with the last part of the working stroke of the piston b, shortly before .it reaches its bottom dead centre, so that, in consequence of the relativel great pressure above atmospheric, still obtaining in the cylinder in this part of the stroke, combustion gases can pass from the cylinder to the Vpipe m.A

This flowing away of the waste gases continues up to t e positive closing'of the valve k, occurring immediately before the end of the explosion stroke, which takes place before the piston commences the following exhaust stroke.

During this period, in consequence of the liowing away of gas through the pipe m to the cooler fn, the pressure of the waste gases remainin in the cylinder will have sunk to the sma l pressure above atmospheric obtaining in the pipe m. The gas still remaining in the cylinder at the Iend of the Working stroke is thereupon forced out by the piston b, which is carrying out its exhaust stroke, through the exhaust valve (Z, which is in the open position.

In the diagram, Figure 2, which shows the course of the pressure for normal ignition, the horizontal line C-D represents the small pressure above atmospheric in the` protective gas pipe m, i. e., before the compressor. Theline E-F indicates the pres# sure obtaining in the last part of the explosion stroke at the moment of the opening of the controlled outlet'member k in the interior of the cylinder a and'amounting to approximately 5-7 atmospheres.

4The point 04 of the expansion line corresponds to the moment of opening and the point S to the moment of closing of the valve la, while the point A gives the moment of the commencing of the exhaust.

Thus the diagram shows that within the abscissee section from O-f-S, in.consequence of the pressure above atmospheric obtaining in the cylinder, the uantity of gas corresponding to the sha ed triangular surface can, on the valve lo being opened, 'flow o ff from the cylinder a into the pipe m. Within the last abscissae section S-A the further expansion in the cylinder takes place up to the preliminary iiowing out of the gas just before the end of the stroke, which flowing out is followed immediately by the. exhaust period, which takes place during the whole of. the subsequent stroke. The preliminary liowing out and the forcing out of the remainder of the waste gas from the cylinder into the atmosphere takes place in a known manner through thev exhaust valve d, which remains open during this whole period.

If, however, there is a misre, the explosion period will also be omitted and in this case, as shown in Figure 3, the expansion line coincldes with the compression l1ne coropening of the valve lc beyon before the compressor e.

Y any point on the cylinder.

ananas responding to the previousrstroke.v The ordinates ofthese lines do notI extend within the interval of time limitin the period of` the line-.C-D corresponding to the pressure in the pipe m' Hence, in this case, in spite of the opening of the valve k, no

.Y gas mixture can pass from the cylinder a to the protective gas pipe m, but from the latter, in consequence of the pressure above atmospheric obtaining continuously in the same, a small portion of the combustion gas, which has already flowed olf, will iiow back intol the cylinder. During the following exhaust stroke, which commences at the point A the entire unburnt charge will be forced through the valve I out of the cylinder a into the atmosphere.

Thus unburnt gas, containing oxygen can never get intothe protective gas pipe.

In Figure 4 a further constructional form 0f the arrangement described above, working according to the same method, is shown diagrammatically in section.

In this case, the cylinder e of the compressor is not located next to the cylinder a. of the internal combustion engine, but lon it. In this arrangement as well through the di-v rect coupling of the two pistons and f during 'the stroke of the explosion period the flowing olf of the combustion gases from the cylinder as of the internal combustion engine' In this case as well the unburnt gases will not flow oif to the pipem in the case of ,a misfire for the same reasons.

The small losses of protective gas, which occur' in consequence of the backward iiow of small quantities of the combustion gases.

from the pi e m to the interior of the cylinder a in tlie case of misfires and therefore occur only exceptionally, are fully compensated by the advantage of the complete reliability in working, which could hitherto be obtained only with more complicated apparatus and even then not completely.

Forthe rest, the arrangement, as is obv1ous, 1s not dependent on a compressor 4 being used with it, which receives the waste gases directly from the internal combustion engine,` but for conveying the waste gases away other suitable arrangements can be use The member 7c' need not be fitted to the lower end of the cylinder a of the internal combustion engine, but can be connected at In place of the valves, slides or any other cut-olf means may be used with the same effect. It is only essential that the ositive opening of the said member shall on y take place at the moment,

increase when, in consequence of the piston being near the end of the stroke, in the case of misres, theexpansion in the interior of the cylinder has progressed so far that the pressure obtaining within the cylinder at this moment has already fallen below the pressure of the combustion gases in the pipe before the compressor.

Having now described my invention, what claim as new and desire to secure by Letters Patent is l. A method for the production of protective gas by means of an internal combustion engine which consists in 'conducting that portion of the combustion gases which dows from the cylinder of the internal combustion engine into a protective gas pipe during part of the explosion stroke due to the pressure in the cylinder being above the pressure existing in the said protective gaspipe, and allowing the remaining portion of the combustion gases to be conducted out of the c linder of the internal combustion engine into the atmosphere during the following exhaust stroke.

2. A method for the production of rotective gas by means of an internal com ustion engine, which consists in conducting that portion of the combustion gases which ows from the cylinder of the lnterna combustion engine into a protective gas-pipe during part ofthe explosion stroke, due to the pressure in the cylinder being above the pressure existing in the said protective gaspipe and being at a point of the explosion stroke at which the pressure for the corresponding position of the piston of the engine during the compression stroke is lower than the pressure existing in the protective gas-pipe, and allowing the remaining portion of the combustion gases to be conducted out of the cylinder of the internai combustion engine into the atmosphere during the following exhaust stroke.

3 An apparatusconsisting oa sieurrohe internal combustion engine for the production of protective gas according to the method as claimed in Claim l, comprising in addition to the cylinder of the internat cornbustion engine and the usual exhaust member, a cut-ofi' member operating at a pressure above atmospheric to which a protective gas pipe is connected and which is intended to be opened towards the end of the explosion stroke, but be closed again before the stroke is quite completed.

ln testimony vvhereoir` l have signed my name to this specification..

JUSEF MUSE-Mirti Witnesses:

HUGO Kam, ORNTON Konin. 

